1. Field of the Invention
The present invention relates to an image forming device with a mounted replaceable unit which indicates a state thereof depending on whether or not a contained fuse has been blown, a method of checking operation in the image forming device, and a storage medium storing an operation checking program directed to the image forming device.
2. Description of the Related Art
Conventionally, image forming devices (copying machines, printers, facsimiles, and Multifunction Peripherals) generally have mounted units required for image forming operation. Examples of such replaceable units (hereinafter also referred to simply as “units”) include a toner unit for supplying toner used for printing, an imaging unit having a photoconductor, a transfer body and the like.
An image forming device needs to obtain a state of a mounted unit (e.g., information that the unit is new or used) for proper operation. A known structure for obtaining a state of a unit includes a nonvolatile memory or the like contained in each unit, with necessary information stored in the nonvolatile memory.
Also known is a more simplified structure, in which a unit contains therein a component (typically a fuse) whose state value can be electrically changed, and a state of the unit is obtained based on an electrical state of this component.
As an example of the latter structure, Japanese Laid-Open Patent Publication No. 05-040373 discloses a technique of determining whether a unit is new or used based on whether or not a fuse contained in the unit has been blown. Japanese Laid-Open Patent Publication No. 2007-041392 discloses a structure in which a fuse is contained as a circuit for detecting that a replaceable unit is new, and the fuse is blown when it is detected that the unit is new.
When a structure in which a fuse contained in a unit is blown in response to mounting of the unit on an image forming device as described above is employed, operation of a circuit for performing blowing operation (hereinafter also referred to as a “fuse blowing circuit”) can be checked as well during the blowing operation.
When shipped from a factory, such image forming device generally has units required for performing image forming processing already mounted thereon. Namely, the image forming device is shipped after completion of mounting of required units, fuse blowing operation in the units, checking of operation of the fuse blowing circuit, an initialization process on the mounted units, and the like. Stated another way, in an image forming device after being shipped from a factory, fuse blowing operation is not performed in principle for units already mounted at a shipment stage.
A fuse is a relatively expensive component. Accordingly, a fuse contained in a unit already mounted on an image forming device at a shipment stage from a factory (hereinafter also referred to as an “included unit”) could be eliminated to reduce manufacturing costs. Yet even in this case, a new unit to be mounted after the included unit reaches the end of its life needs to contain a fuse.
Fuse blowing operation in a unit also serves to check operation of a fuse blowing circuit, and simply eliminating a fuse in a unit results in inability to check operation of the fuse blowing circuit. It may thus be necessary to additionally perform another method of checking operation (e.g., an operation checking step of inspection by installing a jig dedicated to checking operation of a fuse blowing circuit on an inspection line for an image forming device, and then removing the jig), which rather increases the manufacturing costs.